Ecological crisis
Encyclopedia
An ecological crisis occurs when the environment
of a species
or a population
changes in a way that destabilizes its continued survival. There are many possible causes of such crises:
The evolutionary theory of punctuated equilibrium
sees infrequent ecological crises as a potential driver of rapid evolution.
, there is a decrease in snow-fall, and sea levels are rising. Ecosystems will change or evolve to cope with the increase in temperature. Consequently, many species are being driven out of their habitats.
Polar bears are being threatened. They need ice for hunting seals, their primary prey. However, the ice caps are melting, making their hunting periods shorter each year. As a result, the polar bears are not developing enough fat for the winter; therefore, they are not able to reproduce at a healthy rate.
Fresh water and wetland ecosystem
s are dealing with extreme effects of the increase of temperature. The climate change could be devastating to salmon and trout and to other aquatic life. The increase in temperature will disrupt the current life patterns of the salmon and trout. The cold-water fish will eventually leave their natural geographical range to live in cooler waters by migrating to higher elevations.
While many species have been able to adapt to the new conditions by moving their range further towards the poles, other species are not as fortunate. The option to move is not available for polar bears and for some aquatic life.
was caused by a meteor collision
65 million years ago.
The loss of new species in an ecosystem will eventually affect all living creatures. In the U.S. and Canada, there was a dramatic reduction of shark population along the U.S. east coast. Since then, there has been an increase in population of rays and skates, which in turn has decimated the population of shellfish. The loss of shellfish has reduced the water quality and the size of sea grass beds. Biodiversity
is being lost at a fast rate. The more species there are in an ecosystem, the more resilient it is to evolution.
Seven million square kilometers of tropical forest have vanished in the last 50 years. About two million square kilometers were used for crops, while the remaining five million square kilometers is poor quality land. Turning these unproductive lands back into native forest could capture an estimated five billion metric tons of carbon from the atmosphere every year for 10 to 20 or more years. Reforestation
will have enormous benefits on biodiversity.
In the absence of predators, animal species are bound by the resources they can find in their environment, but this does not necessarily control overpopulation. In fact, an abundant supply of resources can produce a population boom that ends up with more individuals than the environment can support. In this case, starvation, thirst, and sometimes violent competition for scarce resources may effect a sharp reduction in population, and in a very short lapse, a population crash. Lemmings, as well as other less popular species of rodents, are known to have such cycles of rapid population growth and subsequent decrease.
In an ideal setting, when animal populations grow, so do the number of predators that feed on that particular animal. Animals that have birth defects or weak genes (such as the runt of the litter) also die off, unable to compete over food with stronger, healthier animals.
In reality, an animal that is not native to an environment may have advantages over the native ones, such being unsuitable for the local predators. If left uncontrolled, such an animal can quickly overpopulate and ultimately destroy its environment.
Examples of animal overpopulation caused by introduction of a foreign species abound.
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....
of a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
or a population
Population
A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
changes in a way that destabilizes its continued survival. There are many possible causes of such crises:
- It may be that the environment quality degrades compared to the species' needs, after a change of abiotic ecological factor (for example, an increase of temperature, less significant rainfalls).
- It may be that the environment becomes unfavourable for the survival of a species (or a population) due to an increased pressure of predationPredationIn ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
. - Lastly, it may be that the situation becomes unfavourable to the quality of life of the species (or the population) due to raise in the number of individuals (overpopulationOverpopulationOverpopulation is a condition where an organism's numbers exceed the carrying capacity of its habitat. The term often refers to the relationship between the human population and its environment, the Earth...
).
The evolutionary theory of punctuated equilibrium
Punctuated equilibrium
Punctuated equilibrium is a theory in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in an extended state called stasis...
sees infrequent ecological crises as a potential driver of rapid evolution.
The Abiotic Factors
Climate change is starting to have major impacts on ecosystems. With global temperature risingGlobal warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
, there is a decrease in snow-fall, and sea levels are rising. Ecosystems will change or evolve to cope with the increase in temperature. Consequently, many species are being driven out of their habitats.
Polar bears are being threatened. They need ice for hunting seals, their primary prey. However, the ice caps are melting, making their hunting periods shorter each year. As a result, the polar bears are not developing enough fat for the winter; therefore, they are not able to reproduce at a healthy rate.
Fresh water and wetland ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
s are dealing with extreme effects of the increase of temperature. The climate change could be devastating to salmon and trout and to other aquatic life. The increase in temperature will disrupt the current life patterns of the salmon and trout. The cold-water fish will eventually leave their natural geographical range to live in cooler waters by migrating to higher elevations.
While many species have been able to adapt to the new conditions by moving their range further towards the poles, other species are not as fortunate. The option to move is not available for polar bears and for some aquatic life.
Biodiversity Extinction
Vast numbers of species are being annihilated. Every year between 17,000 and 100,000 species vanish from the planet. The speed in which species are becoming extinct is much faster than in the past. The last mass extinctionExtinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
was caused by a meteor collision
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
65 million years ago.
The loss of new species in an ecosystem will eventually affect all living creatures. In the U.S. and Canada, there was a dramatic reduction of shark population along the U.S. east coast. Since then, there has been an increase in population of rays and skates, which in turn has decimated the population of shellfish. The loss of shellfish has reduced the water quality and the size of sea grass beds. Biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
is being lost at a fast rate. The more species there are in an ecosystem, the more resilient it is to evolution.
Seven million square kilometers of tropical forest have vanished in the last 50 years. About two million square kilometers were used for crops, while the remaining five million square kilometers is poor quality land. Turning these unproductive lands back into native forest could capture an estimated five billion metric tons of carbon from the atmosphere every year for 10 to 20 or more years. Reforestation
Reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....
will have enormous benefits on biodiversity.
Overpopulation
In the wilderness, the problem of animal overpopulation is solved by predators. Predators tend to look for signs of weakness in their prey, and therefore usually first eat the old or sick animals. This has the side effects of insuring a strong stock among the survivors and controlling the population.In the absence of predators, animal species are bound by the resources they can find in their environment, but this does not necessarily control overpopulation. In fact, an abundant supply of resources can produce a population boom that ends up with more individuals than the environment can support. In this case, starvation, thirst, and sometimes violent competition for scarce resources may effect a sharp reduction in population, and in a very short lapse, a population crash. Lemmings, as well as other less popular species of rodents, are known to have such cycles of rapid population growth and subsequent decrease.
In an ideal setting, when animal populations grow, so do the number of predators that feed on that particular animal. Animals that have birth defects or weak genes (such as the runt of the litter) also die off, unable to compete over food with stronger, healthier animals.
In reality, an animal that is not native to an environment may have advantages over the native ones, such being unsuitable for the local predators. If left uncontrolled, such an animal can quickly overpopulate and ultimately destroy its environment.
Examples of animal overpopulation caused by introduction of a foreign species abound.
- In the ArgentineArgentinaArgentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
PatagoniaPatagoniaPatagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...
, for example, European species such as the troutTroutTrout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...
and the deerDeerDeer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species and female reindeer grow and shed new antlers each year...
were introduced into the local streams and forests, respectively, and quickly became a plague, competing with and sometimes driving away the local species of fish and ruminantRuminantA ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...
s.
- In AustraliaRabbits in AustraliaIn Australia, rabbits are a serious mammalian pest and are an invasive species. Annually, European rabbits cause millions of dollars of damage to crops.-Effects on Australia's ecology:...
, when rabbits were introduced (unwillingly) by European immigrants, they bred out of control and ate the plants that other native animals needed to survive. Farmers hunted the rabbits to reduce their population and prevent the damage the rabbits did to the crops. They also brought cats to guard against rabbits and rats. These cats created another problem, since they became predators of local species.
Other examples
Some common examples of ecological crises are:- The Exxon Valdez oil spillExxon Valdez oil spillThe Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24, 1989, when the Exxon Valdez, an oil tanker bound for Long Beach, California, struck Prince William Sound's Bligh Reef and spilled of crude oil. It is considered to be one of the most devastating human-caused...
off the coast of AlaskaAlaskaAlaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
in 1989 - Permian-Triassic extinction eventPermian-Triassic extinction eventThe Permian–Triassic extinction event, informally known as the Great Dying, was an extinction event that occurred 252.28 Ma ago, forming the boundary between the Permian and Triassic geologic periods, as well as the Paleozoic and Mesozoic eras...
250 million of years ago - Cretaceous–Tertiary extinction event 65 million years ago
- Global warmingGlobal warmingGlobal warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
related to the Greenhouse effectGreenhouse effectThe greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere...
. Warming could involve flooding of the Asian deltas (see also eco refugees), multiplication of extreme weatherExtreme weatherExtreme weather includes weather phenomena that are at the extremes of the historical distribution, especially severe or unseasonal weather. The most commonly used definition of extreme weather is based on an event's climatological distribution. Extreme weather occurs only 5% or less of the time...
phenomena and changes in the nature and quantity of the food resources (see Global warming and agriculture). See also international Kyoto ProtocolKyoto ProtocolThe Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...
. - Ozone layerOzone layerThe ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...
depletion. - DeforestationDeforestationDeforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
and desertificationDesertificationDesertification is the degradation of land in drylands. Caused by a variety of factors, such as climate change and human activities, desertification is one of the most significant global environmental problems.-Definitions:...
, with disappearance of many species. - Volcanic eruptions such as Mount St. Helens1980 eruption of Mount St. HelensThe 1980 eruption of Mount St. Helens, a stratovolcano located in Washington state, in the United States, was a major volcanic eruption. The eruption was the only significant one to occur in the contiguous 48 U.S. states since the 1915 eruption of Lassen Peak in California...
and the TunguskaTunguska eventThe Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m...
and other impact events - The nuclear meltdownNuclear meltdownNuclear meltdown is an informal term for a severe nuclear reactor accident that results in core damage from overheating. The term is not officially defined by the International Atomic Energy Agency or by the U.S. Nuclear Regulatory Commission...
at ChernobylChernobylChernobyl or Chornobyl is an abandoned city in northern Ukraine, in Kiev Oblast, near the border with Belarus. The city had been the administrative centre of the Chernobyl Raion since 1932....
in 1986 caused the death of many people and animals from cancerCancerCancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
, and caused mutations in a large number of animals and people. The area around the plant is now abandoned by humans because of the large amount of radiation generated by the meltdown. Twenty years after the accident, the animals have returned.
Further reading
- "Global Warming Said Devastating Aquatic Ecosystems" by Brad Bohlander
- "Death of a Small Planet" by Murray BookchinMurray BookchinMurray Bookchin was an American libertarian socialist author, orator, and philosopher. A pioneer in the ecology movement, Bookchin was the founder of the social ecology movement within anarchist, libertarian socialist and ecological thought. He was the author of two dozen books on politics,...
- "The Ecological Crisis as Part of the Present Multidimensional Crisis and Inclusive Democracy" by Takis FotopoulosTakis FotopoulosTakis Fotopoulos , born , is a political philosopher and economist who founded the inclusive democracy movement. He is noted for his synthesis of the classical democracy with the libertarian socialism and the radical currents in the new social movements...
, (International Journal of Inclusive DemocracyInclusive DemocracyInclusive Democracy is a political theory and political project that aims for direct democracy, economic democracy in a stateless, moneyless and marketless economy, self-management and ecological democracy...
, vol 3, no 3, June 2007) - "Myths on the Ecological Crisis" by Takis Fotopoulos
- "Polar Bears Send an 'SOS'" by WWF
- The Paradox of Wealth: Capitalism and Ecological Destruction by John Bellamy Foster and Brett Clark